How to fix peak/pinch in one vertex (after subdivision)
Try the following and report back:


Verify no duplicate verts
Verify Normals Outside &amp; In
Verify Normals are not bugged by doing the "Set From Faces" Normals (use F3 to search)
Checked for Clear Edge (Sharp Edge)
Try smoothing Object
Loop cut and added additional loop for potential topology issue...


And as a final check, adjust your Auto Smooth Angle...

Edit I'm adding another check on the list. Sometimes Recalculating normals is not enough and you need to force all normals to be perpendicular (YES THEY WILL VISUALLY LOOK FINE)

Set From Faces in the Shading tab of the Tool Shelf.

What's happened is your normals have got bent out of shape in a weird way that the usual Ctrl + N make normals consistent doesn't see as a problem.